Abstract : The NHBP (Non-hypergolic bipropellant) Design provides certain operational and design features which are not available to solid propellant gun systems. These are as follows: (1) High gun performance can be achieved at relatively moderate gun sizes since the receivers need not be sized to handle large cartridge cases. (2) Since only the projectiles are stored and transported, the ammunition supply system weight, volume, and power requirements are considerably less than comparable performance solid propellant system. (The acid and, in some cases, the N2 pressurizing tank, is stored in the ammunition drum internal to the projectile storage volume.) (3) The stationery barrels do not introduce tangential velocity components into the projectile trajectory. (4) Rapid acceleration to full firing rate is achieved because of the small masses that are rotated. If desired, the drive cam can be continuously rotated with the hydraulic system locked out so that almost instantaneous full firing rates can be achieved. Variable speed drive can be incorporated, permitting a variable firing rate. (5) The NHBP combination eliminates the propellant explosive hazard in the ammunition storage system. (Author)